How to register a new module created in vendor in Magento 2.3

Recently I try create a new module in vendor source path ,my new module is hosted in github, and i get installed via composer configuration, and it was downloaded in “vendor/namespace/name_module” , after i run command

bin/magento setup:upgrade

Composer could not find the config file:

/mage/var/composer_home/composer.json

I replace it whith a composer.json like to

{}

But not really work,

Looking for other modules in vendor, i found “sub composer.json ” from each module in vendor

    {
"name": "name_space_vendor/name_module",
"description": "Vendor Module description",
"type": "magento2-module",
"version": "1.0",
"license": [
  "Apache-2.0"
],
"require": {
  "php": "~7.3.0||~7.4.0",
  "magento/framework": "*"
},
"suggest": {
  "magento/module-shipping": "*"
},
"autoload": {
  "files": ["registration.php"],
  "psr-4": {
    "VendorNameSpace\NameModule\": ""
  }
}
}

But really how to run it, or really how to i shall install